In high intensity focused ultrasound (HIFU) an array of ultrasonic transducer elements are used to form an ultrasonic transducer. Supplying alternating current electrical power to the transducer elements causes them to generate ultrasonic waves. The ultrasonic waves from each of the transducer elements either add constructively or destructively. By controlling the phase of alternating current electrical power supplied to each of the transducer elements the focal point or volume into which the ultrasound power is focused may be controlled.
To ease the pain and suffering of some cancer patients, HIFU bone therapy has been used to destroy nerves on a restricted bone surface area. Current HIFU bone therapy applications work by placing cells or sonication points of various sizes either on the bone surface or behind it. To treat a whole bone surface, many points may need to be sonicated. Patients suffering from bone cancers may find it extremely difficult to remain still during a long procedure.